The present invention relates to an apparatus for manufacturing a three-dimensional object layer by layer from a powdery constituent material.
From DE 195 14 740 C1, an apparatus and a method for manufacturing a three-dimensional object by laser sintering are known, wherein application and smoothing of a layer of the powdery constituent material in a working plane is carried out by an applicator in form of a blade. At its lower edge on the side showing towards the application direction, the blade has a chamfer serving for compacting the applied powdery constituent material. On the side opposite to the application direction, a further chamfer is formed which serves for smoothing an already compacted layer. A modified embodiment has roundings instead of chamfers.
In the practice, the optimum values for the various dimensions of the blade depend on different parameters, among others on the layer thickness of the layer to be applied and on the material properties of the powdery constituent material. Values are selected which lead to acceptable results under different known and imaginable conditions. Due to such a tradeoff, it is possible to obtain an acceptable process for different conditions. However, if a powdery constituent material is used whose material properties significantly differ from the average of the imaginable materials, it is possible that during the application of the layer the optimum results are not achieved, so that another form of the blade and/or another distance from the working plane would be required.
However, replacing the blades at such an apparatus is time consuming, since the parallelism of the blades to the working plane and the correct distance from the working plane have to be exactly adjusted every time.